Fabric stripper



Patented June 16, 1 931 'NITE'D SA'E'E rENr oFFicE I WOLF KRITCHEVSKY AND HAROLD C. PRUTSMAN, OF CHICAGO, ILLINOIS, ASSIGNORS TO R/IT PRODUCTS CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAP in a practical wane No Drawing.

Our invention relates to a composition of matter intended for use as a color remover or stripper for dyed fabrics.

Due to the extensive practice of this art, both commercially and in households, there is a large andgrowing demand for a product that will accomplishtlie desired result in a satisfactory manner. The class of chemicals most generally used for this purpose is that known as sulphites, hydrosulphites and sulphoxylates. A most commonly used composition consists of a mixture of zinc dust and sodium bisulphite which, in a watersolution, evolves hydrogen and "forms a chemical known as zinc'hydrosulphite. A well known chemical of this class is sodium hydrosulphite of the general formula Na S O known commercially in this country as lykopon, bleacan, decrolin, etc.

This chemical when boiled in water either alone or in the presence-of an alkali or acid evolves hydrogen according to the formula or equation formation of sodium hydrosulphite forn'ialdehyde, otherwise known as sodium sulphoxylate. This product is somewhat more stable than hydrosulphite alone but it is not stable sense.

Another method of eifecting stabilization.

. is to form normal zinc salts known as zinc hydrosulphites or protolineor zinc sulphoxylate hydrosulphite. These represent an im'- provement over and must be isolated from air and moisture.

Inview of the fact that all of the sub- Application filed April 30,

:hydrosulfurous acid lykopon but it is not stable FABRIC STRIPPER 1930. Serial No. 448,784.

stances heretofore mentioned are water soluble, it has been proposed that a desired result might be secured by forming the insoluble derivatives, and zinc salts, known as basic zinc sulphoxylate hydrosulphite has been developed, otherwise known as rongalite or formopon-extra. The substances are considerably more stable in air, due to the fact that they are insoluble in water. However, inorder to use them they must be combined in an acid solution to neutralize the zinc salt and liberate the free acid. The result is a compound much weaker than straight sodium hydrosulphite. However, even these derivatives are not stable for indefinite periods in open air. i

In order to merchandise a package product for household use it is difiicult, if not impossible, to" provide hermetic sealing. For that reason, we have for some years marketed a product under Patent No. 1,524,737 consisting of a mixture of a hydrosulphite and a solid acid-reacting substance. This product is an improvement over the art, but still not entirely satisfactory. It is for this reason that we have carried on a series of experiments looking toward the development of a stripping substance that could be marketed in package form'and that would be stable under all atmospheric conditions.

As the result of our experiments,,we have found that the main reason for the decomposition ofthe hydrosulphite compounds was that the substance is hygroscopic and decom poses in the presence of air and moisture. YVe have, therefore, determined that if the hydrosulphite particles are enveloped in, a water-proof or water-resistant film, the oxygen of the air and moisture will be excluded and the substance will remain'stable indefinitely. I

In speaking of hydrosulphites, we include under that name all compounds that belong to this class. It may include thesalts of SOgH SOH It also may include the different salts of .the condensation product hydrosulfurous of the general formula acid, or its salts with formaldehyde which have the following formula known as formaldehyde sulfoxalic acid and or mixtures thereof. These compounds are mopon which is sodium sulphoxylate formaldchyde or basic zinc sulphoxylate formaldehyde, technically known as Formopon-extra,

Rongalite, etc.

There are many other formulae and many other technical names but for brevity the substances are herein called hyiiosulphites, as they belong generally to the "hydrosulfite class, the hypothetical hydrosulfurous acid being the parent substanceof the whole class.

We have found that when sodium hydrosulphite or one of the derivatives heretofore mentioned is intimately mixed with an oily substance, the product will remain stable even when it is exposed to the air for practically an indefinite period. An oily substance that will accomplish this result may be a hydrocarbon such as petrolatum, kerosene, or paraffine, or a metallic soap that is insoluble in 7 water, such as aluminum stearateor even an odinary anhydrous soap, such as sodium stearate, or a sulphonated soap or a vegetable oil, such as castor oil, corn oil, or a sulphonated oil, or a fatty acid like oleic acid, stearic acid, sulphonated fatty acid, or a napthenlc acid or a sulphonated petroleum residue, etc.

lVe have determined that when a quality of any of the mentioned oily substances varying from 2%% to 5% and up of the total amount of hydrosulphite, depending on the character of the oily substance, is initimately mixed therewith, an oily film is formed around each particle of the hydrosulplnte thus providing an encasing envelope that serves to exclude air and moisture for practically an indefinite period.

A product such as described can be used in.

that form in operations where an aqueous solution is not necessary. In cases where the enveloping oily water-resistant film is soap or a. sulfonated soap, the product could' be used in water without any other chemicals, as

the water resistant but soluble film will dissolve in excess of water and liberate the hydrosulphite for action. v

Or it may be merchandised in that form for household use in a water solution with instructions to the user to supply to the splution an agent that will serve to act on the oily ,ponifiable oil; or an emulsifying substance such as ordinary soap, the selection of the agent depending on the character of the oily substance employed for enveloping the stripping chemical.

In the use of these agents the oily substance is freed from the hydrosulphite and permit- 1 ted to enter into solution or suspension. In

the use of the saponifying agent, particularly where an excess of alkali is used, there will be formed an alkaline solution that will assist in the stripping action.

We may prefer to also add to the solid compound other substances such as solvents,-

assistants, penetrators, and fillers, so long as any such added substance does not interfere with the function of the oily substance.

In order to exemplify our invention, we shall cite a few compositions of matter that we suggest for use.

60 parts of sodium hydrosulphite are intimately mixed thoroughly with 40 parts of sulphonated oil or sulphonated soap until the oily film thorou sulphite and thereby excludes it from air and moisture. This product could be used as such, or mixed with a diluent or assistantlike salt, sugar, etc., to turn it into a'solid mass which could be granulated or pressed into cakes.

This product will keep for a long time under ordinary climatic conditions without any deterioration, and in order to be used it has to be used in an excess of water, which water will dissolve the moisture-resistant, but water-soluble film and liberate the hydrosulphite for action.

Another example of a composition of mat- 'hly envelopes the hydroter that would be within the spirit of this invention is as follows: 30 parts of neutral zinc sulfoxalate formaldehyde are enveloped with 30 parts of petrolatum until the oily film surrounds the chemical thoroughly and protects it from the excess of moisture. Then the paste is mixed thoroughly with 40 parts of a solid acid-reacting substance like sodium bisulphite or tartaric acid or the free acid of an alkylated vpolynuclear hydrocarbon or sulfonic acid or an aromatic hydrocarbon.

The finished product is stable and when thrown into hot water, the oily substance separates from the hydrosul hite and the hydrosulphite combines with t 'e solid acid and reacts with it to liberate hydrogen.

We have not attempted herein to specify or mention all possible substances that may be used or that will function to protect the hydrosulphite from deterioration, depending on.the disclosures as made to describe the principle of the invention.

We claim:

1. A composition of. matter that is stable under ordinary climatic conditions, consisting of a mixture of a stripping chemical of the hydrosulfite class and a salt of a saponified substance belonging to the cla ss'of oils, fats and waxes that will en'case the individual particles of the stripping chemical and tend ,to exclude air and moisture. therefrom.

2. A composition of-matter that is stable under ordinary-climatic. conditions, consisting of a mixture of a stripping chemical of the hydrosulfite class and-a salt of a saponified substance. belonging to the class of oils, fats and waxes that will enc'ase the individual particles of the stripping chemical and tendto exclude air and. moisture therefrom and that will' be released-in an excess water solution and .free the chemical so that it may enter into solution. 4

under ordinary climatic 3. A composition of matterthat is stable conditions consisting of a'hydrosulphite salt and a salt of a saponified substance belonging to the class of "oils, fats and waxes intimately mixed with said hydrosulphiteand acting to envelope the particles thereof with a film.

feri'ng with y the hydrosulfitclass,

' particles of the stripping 4. A compos'tion of matter that is stable under ordinary climatic conditions consisting of a hydrosulphite salt and a salt of a saponified substance belonging to theclass of oils, fats and waxes intimately mixed with said hydrosulphiteand acting to envelopethereof with a film and that.

to exclude air and moisture therefrom and tion and free the chemical so that it may enter into solution, and a substance that will assist in solidifying said composition.

6. A-composition of matter consisting of a chemical of the hydrosulfite class and-a salt ture therefrom.

sodium hy rosulphite of saponified su stance" belonging to the class of oils, fats and waxes intimately mixed therewith and acting to envelope the particles of the chemical and exclude a r and mois- 7. A com osition o tter consisting of chemical and tend and a substamtially anhydrous salt of a sulfonated oil intimately mixed therewith and acting to envelo the particles of the chemical and exclude an and moisture therefrom.

8. A composition of matter consisting of sodium hydrosulphite, a substantially anhydrous salt of a 'sulfonated oil intimately mixed therewith and acting to envelope the particles of the chemical'and exclude air and moisture therefrom, and anhydrous soda ash. In testimony whereof we have aflixed our signatures. WVOLF .KRITCHEVSKY. a HAROLD C. PRUTSMAN.

that will be released in an excess water SO11];- 

